Franckeite (Var: Potosiite), Franckeite, Galena
San Jose Mine, Oruro City, Cercado Province, Oruro Department, Bolivia
Miniature, 4.0 x 3.4 x 1.7 cm
From the great find of 2004. This specimen is a very attractive, very rare, fine, crystallized specimen of Potosiite consisting of several, extremely rare, highly lustrous, heavily striated, tabular blades (some are twinned) of measuring up to 5 mm sitting atop crystallized and the equally rare triclinic lead, tin, iron, antimony sulfosalt Franckeite with minor crystals of Galena. The crystals of Potosiite on this specimen are exceptionally large. Before these new specimens were discovered, some of the largest known crystals of Potosiite were massive, un-crystallized, granules less than 1 mm in most cases. This find completely redefined Potosiite.